Exercising my 4WD on a regular basis

[ahmed.]

Hi, I know questions like this have been asked numerous times in the past. I have looked at some posts that were previously made about this but it seems like I'm always reading that conflicts on contradicts what I just read before.

I have a 2007 V6 4th gen. Part time 4WD. 99% of my usage is done in 2WD. In an effort to make sure that everything stays functional I try to drive for a day each month in 4HI with the center diff unlocked. What I have never done so far in the two years I've owned the vehicle is enter 4LO or lock the center diff. I want to make sure I have the ability to do so should a situation come up where I need to be in 4LO and/or have the center diff locked.

In order to make sure that everything stays functional, could I just take a slow drive around my neighborhood in 4LO every month or every couple months with the center diff unlocked? And to ensure that my center diff locking capability stays functional would it be sufficient if I went to an empty parking lot and locked the center diff and drove straight, forward and/or reverse, but completely straight with no turning of the steering wheel?

I don't have any places around me where I could go off road, but I do have plenty of areas where I could just drive in a straight line for a bit.

 

[Nuke]

I previously owned a 2nd gen and 3rd gen and currently own a 4th and 5th gen. I try to make it a habit to drive in 4WD hi every few months but only when the roads are wet (the 2nd gen wasn’t solenoid operated). I might drop it into 4lo once in a blue moon. I've never had a failure to engage.

 

[newton22]

Yes you could but it's not about how long you leave it in 4H or 4L, it's about just actuating the actuator. I'll literally engage 4L pulling out of a parking spot and go back into 2WD before pulling out onto the street and I'll be good.

 

[ukrsindicat]

I think this is a good habit.

I just recently test drove 06 4Runner with part-time 4WD.
It drove great in 2WD and 4-HI. But as soon as I turned on the 4-LO, the engine started misfiring and the "check engine" went on. I bowed out from that purchase. Not to hijack the thread, but does anyone know the reason for vehicle to behave that way?

 

[Nuke]

...it's not about how long you leave it in 4H or 4L, it's about just actuating the actuator...

IIRC, at least in the OM for one of my older gen T4Rs, Toyota recommended driving with 4WD engaged for about 10 miles once a month. I'd check my 5th gen's manual but it's in an outbuilding and I don't think I have the pdf on this tablet.

 

[newton22]

IIRC, at least in the OM for one of my older gen T4Rs, Toyota recommended driving with 4WD engaged for about 10 miles once a month. I'd check my 5th gen's manual but it's in an outbuilding and I don't think I have the pdf on this tablet.

Good to know. But what difference would it make driving it for 1 mi or 10 mi in 4WD? Just to get certain transfer case/front diff gears lubricated?

With these trucks, the issue always seems to be the transfer case actuator itself.

 

[ahmed.]

So just to clarify:

- In order to exercise 4LO, I can just drive around my neighborhood slowly, every once in a while? I don't have to worry about any sort of binding up due to driving on pavement and making turns?

- For the differential, I can drive on pavement just as long as its in a straight line with no turning whatsoever?

Furthermore (just for additional clarification), there's no issue if I were to leave my car in 4HI with the differential unlocked, and just drove like that full time year round right? My understanding is that this configuration is the exact same as what the V8 guys drive in by default.

 

[eleven14]

Some answers below in red...

So just to clarify:

- In order to exercise 4LO, I can just drive around my neighborhood slowly, every once in a while? I don't have to worry about any sort of binding up due to driving on pavement and making turns? Correct, as long as the center diff is unlocked

- For the differential, I can drive on pavement just as long as its in a straight line with no turning whatsoever? Correct, this is ONLY with center diff locked

Furthermore (just for additional clarification), there's no issue if I were to leave my car in 4HI with the differential unlocked, and just drove like that full time year round right? My understanding is that this configuration is the exact same as what the V8 guys drive in by default.Accurate

 

[southern_runner]

So just to clarify:

- In order to exercise 4LO, I can just drive around my neighborhood slowly, every once in a while? I don't have to worry about any sort of binding up due to driving on pavement and making turns?

- For the differential, I can drive on pavement just as long as its in a straight line with no turning whatsoever?

Furthermore (just for additional clarification), there's no issue if I were to leave my car in 4HI with the differential unlocked, and just drove like that full time year round right? My understanding is that this configuration is the exact same as what the V8 guys drive in by default.

-I'd never put it in 4Lo on pavement, straight line or not. Find a nice gravel road, a grassy field or some dirt.

-Same for locking the diff, I wouldn't do it on pavement.

-For your third question about 4Hi, I have the V8 4wd so it's full time 4wd. I would think as long as the center diff is unlocked then you could drive it this way. There is a limitation if you're shifting from 2H to 4H, and I believe that's 62mph. You should be doing less than that when going from 2H to 4H

 

[southern_runner]

Here's another good explanation:

"With a locked center connection -- part-time 4WD (classic 4WD) or full-time 4WD with center differential locked (cdl on) -- the front and rear drive shafts rotate at the same speed, just as if there were one shaft from front to back. During a turn, all four wheels turn in a different size arc and, thus, different speeds. This can't be compensated for by the front and rear diffs because when each side of the diff has traction, any increase in speed on one side is matched by an equal reduction on the other side.

Since it's the average speed of the two front wheels and the average speed of the two rear wheels that matters, the effective result is a comparison of one arc for the fronts and one arc for the rears. So, during a turn the rear wheels follow a smaller arc (1 averaged arc) than the fronts and want to turn more slowly. Since the locked drive shaft in between can only rotate at one speed, opposite forces are created between front and rear, with the braking force (skid) being in the front and the drive force (slip) in the back. With same size tires equally inflated, this conflict is near zero when the vehicle is going straight, but starts to come into play as the steering wheel is turned, starting out mild but quickly becoming more severe as the turn is made tighter, resulting in an increasingly heavy feel in the steering wheel and a sensation of brakes being applied.

Near the extremes, tires can audibly and visibly skip and skid. On slippery surfaces, this can occur more easily but on pavement more stress is imparted to the drive train, especially at very low speed where releasing energy through the tires is more difficult and there is no momentum to unweight the inside tires during a turn. It also results in handling changes that usually make the car want to turn a little wider (understeer) than it normally would, due to the tendency of a front wheel to skid. (The words bind and windup, in combination with various parts of the drive line - differential, transfer case, axle, transmission - are terms often used to describe this phenomenon. In other domains, a separate phrase - Tight Corner Braking - is also widely used)."

 

[ahmed.]

Some answers below in red...

Awesome, thank you!!

 

[Flesh Eater]

High quality fluid could probably help a lot as well. The transfer case is usually neglected on fluid changes.